by Kim Hjelmgaard and John Bacon, USA TODAY

by Kim Hjelmgaard and John Bacon, USA TODAY

Evidence continued to build Tuesday indicating Malaysia Airlines Flight 370 made a sharp, deliberate turn westward before disappearing from the world's air traffic control screens.

NBC News reported, based on anonymous sources, that the jet's diversion to the west from its intended flightpath was key-punched into the plane's flight control computer at least 12 minutes before the co-pilot said "All right, good night'' to controllers on the ground.

CNN, citing a Royal Thai Air Force spokesman, reported Tuesday that Thailand's military radar was receiving normal flight data from the Boeing 777-200 when it suddenly disappeared from its radar March 8. Six minutes later, the Thai military detected an unknown signal, possibly Flight 370, heading the opposite direction, CNN said.

And The New York Times, citing unnamed American officials, reported that the plane's turn to the west was likely programmed into the airplane's computer controls by someone in the cockpit rather than a manual operation of the plane's controls. That was seen as one more piece of evidence suggesting the plane was intentionally diverted and increasing investigators' scrutiny of the pilots, the paper said.

Flight 370 was flying from Kuala Lumpur to Beijing with 239 people aboard on March 8 when it lost contact with air traffic control shortly after 1 a.m. local time. Malaysian officials have said evidence thus far indicates the plane was deliberately flown off course, turning west and traveling over the Indian Ocean.

China is also hunting for the plane over its own territory, state media reported Tuesday. Beijing said it has found no terrorism links to the 154 Chinese nationals that were on the jetliner.

Chinese Ambassador to Malaysia Huang Huikang said background checks on Chinese nationals didn't uncover any evidence suggesting they were involved in a hijacking or an act of terrorism against the plane, according to the state Xinhua News Agency.

The remarks will dampen speculation that Uighur Muslim separatists in far western Xinjiang province might have been involved with the jet's disappearance.

China has deployed 21 satellites to help in the search, reports said.

In an update to the search-and-rescue mission Tuesday, Malaysia's acting Transport Minister Hishammuddin Hussein said that every country involved in the search that has access to satellite data has been contacted. He said also that the search involving 26 countries extends over 2.24 million square nautical miles.

Separately, a U.S. warship has ended its search of the Indian Ocean. Pentagon officials told news organizations that the USS Kidd, an Arleigh Burke-class destroyer, will end its six-day search and resume normal duties with the 7th Fleet.

Officials said that as the search area has expanded to two specific "corridors" - one in a northerly direction toward central Asia; the other south toward Australia - long-range aircraft are better suited for trying to locate the missing Boeing 777. Navy P-3 and P-8 aircraft will continue searching for any sign of the jet. Those planes can cover up to 15,000 square miles in nine hours.

Earlier, Hishammuddin said that 10 days into the investigation nothing had been ruled out, including hijacking, sabotage, pilot suicide or mass murder.

"The fact that there was no distress signal, no ransom notes, no parties claiming responsibility, there is always hope," Hishammuddin said.

The unprecedented hunt is taking place as preliminary investigations revealed that the plane's co-pilot apparently spoke the last words to air traffic controllers.

Malaysia Airlines CEO Ahmad Jauhari Yahya said the co-pilot of the plane was probably the person who calmly said, "All right, good night."